How severe is CVE-2025-49596?

No CVSS score has been assigned to CVE-2025-49596 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-49596?

CVE-2025-49596 affects the following packages: @modelcontextprotocol/inspector (npm). Ecosystems affected: npm.

How do I fix CVE-2025-49596?

Update @modelcontextprotocol/inspector to 0.14.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49596 is resolved across your whole dependency graph.

How do I detect CVE-2025-49596 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @modelcontextprotocol/inspector, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-49596 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2025-49596 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-49596 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-49596?

CVE-2025-49596 has an EPSS (Exploit Prediction Scoring System) score of 44.5%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2025-49596?

CVE-2025-49596 is classified as Missing Authentication (CWE-306). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Is there exploit tooling available for CVE-2025-49596?

A Nuclei detection template exists for CVE-2025-49596, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2025-49596 published, and has it been updated?

CVE-2025-49596 was published on June 13, 2025 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2025-49596 — @modelcontextprotocol/ins…

Fix: modelcontextprotocol/inspector@50df0e1

CVE-2025-49596 is a Missing Authentication vulnerability in @modelcontextprotocol/inspector. EPSS puts its 30-day exploitation probability at 44.5% (99th percentile). A fix is available for @modelcontextprotocol/inspector — see the affected versions and patch details below.

MCP Inspector proxy server lacks authentication between the Inspector client and proxy

Also known asGHSA-7f8r-222p-6f5g

Published

Jun 13, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-49596.

EPSS Exploitation Probability

via FIRST.org ↗

44.5%probability of exploitation in next 30 days

High Risk0.00%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

87other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@modelcontextprotocol/inspectornpm

771Kdownloads / week

Description

The MCP inspector is a developer tool for testing and debugging MCP servers. Versions of MCP Inspector below 0.14.1 are vulnerable to remote code execution due to lack of authentication between the Inspector client and proxy, allowing unauthenticated requests to launch MCP commands over stdio. Users should immediately upgrade to version 0.14.1 or later to address these vulnerabilities.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@modelcontextprotocol/inspector`	all versions	0.14.1`npm install @modelcontextprotocol/inspector@0.14.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @modelcontextprotocol/inspector, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @modelcontextprotocol/inspector to 0.14.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49596 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

How to detect CVE-2025-49596

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2025-49596 -u https://target

Template: MCP Inspector < 0.14.0 UnauthenticatedRemote Code Execution
Severity: critical
Impact: Unauthenticated attackers can launch arbitrary MCP commands over stdio due to lack of authentication between Inspector client and proxy, enabling remote code execution.
Remediation: Users should immediately upgrade to version 0.14.1 or later to address these vulnerabilities.

Template by ProjectDiscovery nuclei-templates (ye11oc4t), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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